Oil drain intervals for internal combustion engines are determined by engine manufacturers through rigorous testing. However, a manufacturer cannot simulate all the conditions under which an engine can subject the lubricating oil to. Determining the quality of the in-service lubricating oil in-situ would provide a more accurate assessment of when the oil should be changed. In addition to assessing quality, assessing oil chemical constituents of the in-service lubricating oil in-situ would be useful.
Similarly, the reliability and/or performance of high pressure common rail diesel fuel injection systems may be adversely impacted by the presence of certain contaminants in the fuel, such as water. Typically, the end user would not be aware of the presence of these contaminants until engine performance has been impacted. As such, the ability to detect the presence of contaminants and advise the operator or service personnel accordingly is desirable.
A polymeric bead matrix (PBM) sensor probe is a known type of sensor used to sense the quality of a fluid such as oil. Examples of PBM sensor probes and how they work are described in U.S. Pat. Nos. 5,435,170; 5,777,210; 5,789,665; 7,521,945; and 7,928,741. It is known to use PBM sensors on oil sumps in engines.